The BreakIterator class (in java.text) is used to identify text boundaries such as words, sentences, lines, and characters. It is locale-sensitive and critical in text-processing applications like editors, search tools, and word counters.
Key Features:
- Locale-aware breaking of text into Words,Sentences,Lines,Characters
- Supports internationalized text segmentation
- Abstract class with factory methods for different break types
Commonly Used Methods
Simple Program
import java.text.BreakIterator;
import java.util.Locale;
public class SimpleBreakIteratorExample {
public static void main(String[] args) {
String text = "LotusJavaPrince is teaching Java. They love it!";
BreakIterator iterator = BreakIterator.getSentenceInstance(Locale.ENGLISH);
iterator.setText(text);
int start = iterator.first();
for (int end = iterator.next(); end != BreakIterator.DONE; start = end, end = iterator.next()) {
System.out.println("Sentence: " + text.substring(start, end));
}
}
}
/*
Sentence: LotusJavaPrince is teaching Java.
Sentence: They love it!
*/Problem Statement
Paani and Mahesh are creating an AI-based writing assistant. To provide suggestions and feedback, they need to analyze each word and sentence in a given article. The system should split the text into sentences and then into words, using BreakIterator for accurate boundary detection that works across different locales.
import java.text.BreakIterator;
import java.util.Locale;
public class TextAnalyzer {
public static void main(String[] args) {
String article = "Mahesh loves Java. LotusJavaPrince teaches him well. They build amazing programs.";
// Sentence segmentation
BreakIterator sentenceIterator = BreakIterator.getSentenceInstance(Locale.ENGLISH);
sentenceIterator.setText(article);
int sentenceStart = sentenceIterator.first();
for (int sentenceEnd = sentenceIterator.next(); sentenceEnd != BreakIterator.DONE; sentenceStart = sentenceEnd, sentenceEnd = sentenceIterator.next()) {
String sentence = article.substring(sentenceStart, sentenceEnd);
System.out.println("\nSentence: " + sentence.trim());
// Word segmentation within the sentence
BreakIterator wordIterator = BreakIterator.getWordInstance(Locale.ENGLISH);
wordIterator.setText(sentence);
int wordStart = wordIterator.first();
for (int wordEnd = wordIterator.next(); wordEnd != BreakIterator.DONE; wordStart = wordEnd, wordEnd = wordIterator.next()) {
String word = sentence.substring(wordStart, wordEnd).trim();
if (!word.isEmpty() && Character.isLetterOrDigit(word.charAt(0))) {
System.out.println(" Word: " + word);
}
}
}
}
}
/*
Sentence: Mahesh loves Java.
Word: Mahesh
Word: loves
Word: Java
Sentence: LotusJavaPrince teaches him well.
Word: LotusJavaPrince
Word: teaches
Word: him
Word: well
Sentence: They build amazing programs.
Word: They
Word: build
Word: amazing
Word: programs
*/The BreakIterator class is vital for text boundary analysis, especially for internationalized and language-aware applications.
- Building editors, translators, summarizers, or NLP tools
- Need locale-sensitive sentence or word segmentation
- Handling user input, search indexing, or grammar checks